I'm no fan of ICE – a very large percentage of my friends in the US are immigrants, and I generally want my country to be a welcoming one. ICE has certainly committed unethical and probably illegal acts (probably true of most federal agencies).
But to expect that a _federal agency_ will be denied service from a private entity, especially for essentially political reasons, is lunacy. It'd attract extreme negative attention from the rest of the government, and great fear from all paying customers that an internet mob could separate them from their code at any time.
We should absolutely be lobbying hard for changes to immigration law, the restrictions placed on ICE, and justice for their wrongdoings.
But I can't see how this helps improve immigration, and it certainly seems likely to cause a lot of negative consequences for GitHub. The employees are putting their employer in a "damned if they do, damned if they don't" situation.
EDIT: Just to clarify, I love the vision of a world where executives don't take actions their workers will protest. I think that in order to get there, the protests need to be reasonable, and I think this one isn't.
EDIT DISCLAIMER: I own a small amount of MSFT stock, which was not on my mind as I wrote this. I use GitHub's free service and have no other relationship I can think of with MSFT or GitHub.
A company I work for is free to take the contract, and I'm free to tell them I don't want to work for them any more because of it.
Trump repeatedly asked his followers to rough up protestors 4 years ago.
You placed your question in the 1920’s. The SS was founded as a bodyguard unit for NSDAP leaders in 1925 and remained purely an organ of the party until 1933 when Hitler became chancellor and the Reichstag passed the Enabling Acts. Up to that point, most of the political violence was carried out by the SA, which was likewise an organ of the NSDAP rather than the government. After the Enabling Acts, the Nazi government deliberately blurred the lines between the German government and the NSDAP, but that is well outside the timeframe you suggested.
To answer your question, I would probably not do business with any part of NSDAP starting in the 1920’s on account of their history of street violence and their platform of abolishing democracy. I would similarly refrain from doing business with the German government as soon as the Reichstag abolished democracy and outlawed every political party other than NSDAP. This would extend to the SS although the SS itself was not especially involved in any of these events.
As you can see, this isn’t a particularly relevant analogy.